Casing hanger apparatus



Sept. 23, 1969 A. G. AHLSTONE CASING HANGER APPARATUS 4 Sheets-Sheet 1Filed Oct. 23. 1965 I vEN roe H1? 71/01? G. Hms TONE p 3, 1969 A. 5.AHLSTONE 3,468,558

CASING HANGER APPARATUS Filed Oct. 23, 1965 4 Sheets-Sheet 4 Hen/w? G.HHLSTONE United States Patent 3,468,558 CASING HANGER APPARATUS ArthurG. Ahlstone, Ventura, Califl, assignor to Ventura Tool Company, Ventura,Calif., a corporation of California Filed Oct. 23, 1965, Ser. No.502,927 Int. Cl. F16] 55/00, 21/00; E21b 19/10 U.S. (ll. 285-18 14Claims ABSTRACT OF THE DISCLOSURE Well bore casing hanger apparatus,including an outer hanger body supporting outer casing and an innerhanger body supporting inner casing and movable to a supporting shoulderon the outer body and locked thereto. A tu- 'bular string lowers theinner body and a packing structure as a unit into the outer body tolocate the inner body on the supporting shoulder, at which time thepacking structure is disposed above and spaced from the inner body. Thetubular string and associated operating apparatus are then released fromthe inner body and suitably manipulated to shift the packing structureinto a sealed position closing an annular passage between the bodies,whereupon the tubular string and associated apparatus are released fromthe packing structure and elevated to the drilling rig.

The present invention relates to casing hanger apparatus, and moreparticularly to apparatus for suspending casing from a well head,performing cementing or other operations in a well bore with respect tosuspending casing, and effecting a pack-oil between the suspended casingand the well head.

In the drilling of oil and gas wells at an underwater site, differentcasing strings are hung to protect strata that have been drilled throughfrom the pressures and fluids which may be required or encountered atgreater depths. In many cases, a special housing or body is provided ator near the ocean bottom to support and seal ofi a casing stringcemented in the well bore. With a drilling rig above water and thespecial housing below water, there are many problems faced in supportinga casing string, locking the casing hanger in place, verifying that thelock is operative, circulating fluid for conditioning, cementing thecasing string, energizing an annular seal, testing the seal, andinstalling a protector which protects the seat and sealing area in thehousing for the next casing hanger that is used in suspending anothercasing string to be lowered within the casing string or stringspreviously installed in the well bore. The problems are accentuated ormade more difficult where the drilling rig is on a floating structureanchored in position, but still capable of moving up and down and fromside to side or other lateral directions.

Heretofore, casing hanger assemblies have required several trips of arunning string into the well bore to assemble all necessary parts to oneanother, and to perform all necessary operations in the running,landing, cementing, sealing and testing in connection with the easingstring, and to protect the seat area for the next succeeding casinghanger to be installed in the well bore. A running string, which may beeither casing or drill pipe,

and a running tool have been used for lowering the casing hanger body toits seat in a special housing at or near the ocean bottom. Fluid can becirculated down through the casing string suspended from the hanger bodyand up through the annular area therearound to the annular area abovethe hanger body to condition the well bore, after which cement is pumpeddown the running string, through the running tool, and down inside ofthe casing string, the cement returns moving up the annular area betweenthe casing and the drilled hole or previously installed casing string,the returns passing back to the drilling rig through the annular areabetween the running string and the pipe which connects the drilling rigto the well bore. The running string and the running tool are thenreleased from the hanger body and returned to the drilling rig.

With the aid of another running tool and running string, the sealassembly is then lowered to the location of the hanger, and by suitablemanipulation of the running string, the seal assembly is installed inplace. The running tool may have provision to seal 01f the bore of thewell so that pressure applied above the seal assembly of the casinghanger will indicate if the seal will hold pressure. After the pressuretest has been performed, the running string and running tool are broughtback or retrieved to the drilling rig.

Another running tool is then used with a running string to lower a seatprotector to the area just above or on the casing hanger just installed,which is the area or region for the next hanger to be seated or sealed.Following the installation of the seat protector, the running string andrunning tool are released therefrom and returned to the drilling rig.

In the performance of the above operations, three round trips with arunning string are required, and three diiferent running tools, all at avery high cost, in view of the expense of operating offshore drillingrigs.

The main purpose or objective of the present invention is to reduceconsiderably the expense of performing the above-noted operations, whichhave, heretofore, been performed separately, by accomplishing them in asingle trip. All of the necessary equipment or apparatus is lowered inthe well bore on a running string after the parts have all beenassembled to one another at the surface. The hanger body with the casingsuspended therefrom, the packer assembly, and the seat protector are allrun in the well bore in a single trip. The hanger body is landed on itscompanion seat, locked in place, fluid circulated for conditioning thewell bore, the casing string cemented in place, the seal providedbetween the hanger and the previously installed hanger or casing, theeffectiveness of the seal tested, and the seat protector installed, allin one trip in the well bore. The running string and the running toolcan be disconnected from the assembly, leaving it in its place,including the placement of the seat protector at its proper location inthe previously installed casing hanger.

In effecting the pack-off, the packing element is subjected tocompression only, inasmuch as torque or twisting action is not imposedthereon. The hanger body can be locked in place before the circulatingand cementing operations commence, so that assurance is had that thehanger cannot be pumped from its companion seat. During such operations,the passage area through the apparatus is comtherethrough. The sealingeffectiveness can be tested before the running tool and running stringare elevated from the hole, so that additional pack-off force can beapplied, and if the seal is still leaking, the running tool and runningstring can be removed and a suitable retrieving tool lowered for thepurpose of retrieving the packing structure and then lowering a properpacking structure into place so that a proper seal can be secured.

This invention possesses many other advantages, and has other purposeswhich may be made more clearly apparent from a consideration of a formin which it may be embodied. This form is shown in the drawingsaccompanying and forming part of the present specification. It will nowbe described in detail, for the purpose of illustrating the generalprinciples of the invention; but it is to be understood that suchdetailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a combined side elevational view and longitudinal section ofcasing hanger and associated apparatus installed in and in connectionwith a well bore underlying a body of water;

FIGS. 2a and 2b together constitute a quarter longitudinal sectionthrough casing hanger apparatus embodying the invention and landed in asurrounding hanger body or housing, the parts being illustrated in theinitial condition which they occupy in lowering the apparatus from thedrilling rig, FIG. 2b being a lower continuation of FIG. 2a;

FIG. 3 is a cross-section taken along the line 33 on FIG. 2a;

FIG. 4 is a cross-section taken along the line 4-4 on FIG. 2a;

FIG. 5 is a cross-section taken along the line 5-5 on FIG. 2a;

FIGS. 6a and 6b together constitute views corresponding to FIGS. 2a and2b, with the casing hanger locked in packed-off condition in apreviously installed hanger, FIG. 6b being a lower continuation of FIG.6a;

FIG. 7 is a section through the apparatus, parts being broken away,illustrating the casing hanger apparatus and a seat protector thereaboveinstalled in a casing hanger body therearound and with the running toolremoved;

FIG. 8 is a cross-section taken along the line 88 on FIG. 212;

FIG. 9 is an enlarged fragmentary, longitudinal section through thepacker portion of the apparatus disclosed in FIG. 6b and FIG. 7 insealed-off condition between the inner and outer casing hanger bodies.

A typical installation of apparatus embodying the invention isillustrated somewhat diagrammatically in FIG. 1, in connection with awell bore A underlying an ocean or other body of water and extendingdownwardly from the ocean floor F. A suitable base structure B issupported on the ocean floor and carries an outer casing C of relativelylarge diameter suspended from a casing hanger body D that rest upon anouter seat E on the base and is locked thereto by a suitable lock ringH. Disposed within the outer casing is an intermediate string of casingJ extending down into the well bore and suspended from a suitable casinghanger body K resting upon a companion tapered seat L in the outer bodyD and suitably locked thereto by a lock ring M. One or more blowoutpreventers N are connected by means of a suitable connector P, such as ahydraulic connector illustrated in my application Ser. No. 476,417,filed Aug. 2, 1965, for Coupling Apparatus for Well Heads and the Like,now US. Patent No. 3,321,217, to the hanger body D, the blowoutpreventers being connected by a suitably hydraulic or other connector Pto a flexible joint S, made of sections, secured to a marine conductorpipe T extending to the drilling rig, which may be located on a drillingplatform or on a floating vessel or structure. An inner string of easingU is disclosed in FIG. 1 as having been locked in packed-off conditionin the intermediate hanger body K and it is in connection with thecasing hanger apparatus W for this inner casing to which the presentinvention is directed.

As disclosed in the drawings, the casing hanger assembly W is connectedto a running tool V, the upper end of which is connected to a suitabletubular running string Y, such as drill pipe, extending through theblowout preventers N, connectors P, flexible joint S and marineconductor pipe T to the drilling rig. As shown in FIGS. 2a, 2b, thehydraulic connector P, which is secured to the outer casing hanger bodyD in the manner illustrated in the above-identified application Ser. No.476,417, includes an adapter 10 above the hanger bodies, the inner endof the adapter clamping a suitable seal ring 11 between it and the upperend of the intermediate hanger body K, this seal ring having a groove 12receiving a seal ring retainer 13 mounted in an internal circumferentialgroove 14 in the coupling adapter. The intermediate hanger body has alower downwardly tapering seat or shoulder 15 above which is located aninternal circumferential ring groove 16 containing a split inherentlycontractable lock ring 17 having an upper inner beveled surface 18.Above the lock ring groove 16 is an elongate internal seal surface 19 ofcylindrical form extending to the seal ring 11 that has another internalcircumferential groove 20 opening through it in spaced relation to thelower groove 16 and containing a split inherently contractable lock ring21 having an upper inner beveled surface 22.

The casing hanger apparatus W includes a body 23 having a lower portion24 threadedly connected to the casing U suspended therebelow. This bodyhas a downwardly facing tapered seat 25 adapted to engage the upwardlyfacing seat 15 in the surrounding hanger body K. Above this seat is areduced external diameter portion 26 providing an upwardly facingshoulder 27 engageable with the lower end of the lock ring 17 when thehanger body 23 is moved past the lock ring, during which time the latteris expanded outwardly within its internal groove 16, then contractingpartially inwardly across the shoulder 27 to lock the hanger body inplace by preventing its upward movement.

Above the lock shoulder 27 is a reduced diameter, extemal, cylindricalseal surface 28 disposed opposite the internal seal surface 19 of thesurrounding hanger body K and in spaced relation therewith when thehanger body comes to rest upon its companion seat 15 to form an annularpassage 29. Above this seal surface, the hanger body has a reducedexternal diameter portion 30 provided with a right-hand thread 31 whichis adapted to mesh with a packer actuating sleeve 32 having a companioninternal thread 33. This packer actuator sleeve 32 supports and canexert an axial force against a pack-off assembly 34 to shorten thelatter and compress it between the opposed sealing surfaces 19, 28, asdescribed hereinbelow. The actuator sleeve 32 and packer assembly 34 aredisposed initially above the upper end of the hanger body 23, as shownin FIGS. 2a, 2b.

The actuator sleeve 32 is connected to a seat protector 35 thereabove,which has a reduced diameter portion 36 piloted within the sleeve 32.The seat protector has a plurality of circumferentially spaced radialtorque pins 37 extending into inverted T-shaped slots 38 in the sleeve.The seat protector 35 carries an external seal ring 39 at its upperportion, which is adapted to seal against the internal cylindricalsurface 19 of the surrounding hanger body K, as described hereinbelow,and this seat protector is connected to a torque sleeve 40, forming partof the running and actuating tool V, by a plurality of circumferentiallyspaced coupling pins 41 on the lower portion of the sleeve disposedwithin companion J-slots 42 in the seat protector. The vertical legs 43of the I-slots open upwardly through an upwardly facing shoulder 44 ofthe seat protector 35, the torque sleeve being welded, or otherwisesuitably secured, to radial ribs 45 welded to the running tool mandrel46, the upper end of which is threadedly secured to a tubular runningstring Y, such as drill pipe extending to the drilling rig above thebody of water.

The mandrel 46 is releasably connected to the hanger body 23 by ahydraulically operated device 50. As disclosed most particularly in FIG.2b, the hydraulically operable connection 50 includes a body 51surrounding the lower portion of the mandrel 46 and having an inwardlydirected flange 52 clamped between the upper end of a drill pipe joint53 threadedly secured to the lower end of the mandrel 46, and a lowerpiston sleeve 54 above the flange, the upper end of which is engageablewith and confined by a downwardly facing mandrel shoulder 55. The body51 has a plurality of circumferentially spaced openings or slots 56 inwhich are disposed latches, locking segments or dogs 57 that have outertapered fingers or lugs 58 adapted to fit within companioncircumferential internal grooves 59 in the casing hanger body. With thelatches 57 in the groove 59, a seal ring 60 on the body 51 seals againstthe casing string U. An annular expander and retainer cylinder 61surrounds the running tool mandrel 46 and has a lower cylinder sleeveportion 62 adapted to move within an annular space 63 between the body51 and the lower piston sleeve 54 to a position behind the lockingsegments or latches 57, to hold them outwardly with their fingers 58within the hanger body grooves 59. The lower sleeve has a tapered nose64 adapted to engage companion tapered surfaces 65 in the upper portionof the dogs or segments 57 for the purpose of shifting such segmentsoutwardly into the grooves 59, the extent of outward movement of thesegments being limited by engagement of their upper and lower terminals'66 with the upper and lower stop portions 67 provided on the body 51 onopposite sides of its slots 56.

The lower sleeve 62 is integral with a cylinder head 70, which isslidable along the periphery of the mandrel 46, and this cylinder head,in turn, is integral with an upper cylinder sleeve 71 slidable along anenlarged diameter portion 72 of the mandrel, which conforms in externaldiameter to that of the lower piston sleeve 54. The cylinder 61 isshiftable hydraulically along the mandrel 46 and within the body 51surrounding it, between a lower position illustrated in FIG. 2b, inwhich the lower cylinder sleeve 62 is disposed behind the segments 57,to maintain them locked within the internal grooves 59 of the casinghanger body 23, and an upper position in which the lower cylinder sleeveis disposed above the lock segments 57, permitting them to retractinwardly fully from the internal body grooves 57, so as to eifect adisconnection between the mandrel 46 and the hanger body 23 (FIG. 6b).

The longitudinal shifting of the cylinder 61 along the mandrel 46 andwith respect to the body 51 is accomplished hydraulically. Thus, fluidcan flow through upper ports 73 extending from the central mandrelpassage 74 into an annular cylinder space 75 between the cylinder head70 and the upper piston head portion 72 provided by the mandrel 46 forthe purpose of shifting the cylinder 61 in a downward direction alongthe mandrel. The annular cylinder member 61 is shifted in an upwarddirection by fluid passing from the central passage 74 in the mandrelthrough a plurality of ports 76 into a cylinder space 77 providedbetween the lower piston sleeve 54 and the periphery of the mandrel 46for action upon the lower surface of the cylinder head 70, urging thecylinder 61 upwardly to a position in which the cylinder head engagesthe upper piston head 72, as disclosed in FIG. 6b, in which the lowersleeve 62 is above the dogs 57 which can be freed from the grooves 59.

The running tool V is connected to the hanger body 23 and the parts ofthe apparatus disposed therearound. The seat protector 35 is connectedto the upper portion of the packing actuator sleeve 32 by virtue of thetorque pins 37 being disposed in the T-slots 38, and the seat protectoris connected to the torque sleeve 40 by reception of the torque pins 41of the latter within the J-slots 42. At the drilling rig, the runningtool V is lowered into the hanger body 23 until the locking dogs 57 areopposite the circumferential grooves 59, at which time the dogs areretracted and the cylinder 61 is disposed in its upper position alongthe mandrel 46. By suitable means, such as disclosed in my applicationfor Apparatus for Hanging Well Bore Casing, Ser. No. 503,047, filed Oct.23, 1965, fluid under pressure is directed from the mandrel passage 74through the upper ports 73 into the upper cylinder space 75 to shift thecylinder 61 downwardly and its sleeve 62 downwardly behind the dogs 57to move them outwardly and place their fingers or lugs 58 fully into thecircumferential lock grooves 59 in the casing hanger body 23, the sleeve62 remaining behind the dogs and holding them locked within the bodygrooves. With the mandrel 46 latched to the hanger body, the lower endof the packer assembly 34 is spaced above the upper end of the hangerbody 23.

It will be evident from the drawings that leakage of fluid underpressure between the various parts to which it is applied is preventedby a suitable seal ring 80 on the cylinder head engaging the peripheryof the mandrel 46, by an upper seal ring 81 on the mandrel slidablyengaging the inner surface of the upper sleeve 71, by an external sealring 82 on the lower piston sleeve 54 engaging the inner surface of thelower cylinder sleeve 62 and by a seal ring 83 on the mandrel below thelower ports 76 engaging the inner surface of the lower piston sleeve 54.The inwardly directed body flange 52 is sealed to the mandrel by sealrings 84 on the latter engaging the flange, leakage of fluid between thelower end of the mandrel and the drill pipe joint 53 therebelow beingprevented by seal rings 85 on the mandrel engaging the inner surface ofthe drill pipe.

When the hanger apparatus W and the casing U suspended therefrom isconnected to the running tool V and lowered through the marine conductorpipe T and the equipment connected thereto therebelow by means of thedrill pipe Y to a position illustrated in FIGS. 2a and 2b, in which thehanger body 23 rests upon its seat 15 and the lock ring 17 hascontracted over the upwardly facing shoulder 27, a by-pass circulatingpassage exists between the hanger apparatus W and the surrounding hangerbody K. As shown, this by-pass apparatus communicates with the annulusin the well bore surrounding the susupended casing U and includes aplurality of circumferentially spaced longitudinal fluid passages 91extending through the hanger body 23 to the annular passage 29 betweenthe opposed seal surfaces 19, 28. Fluid can then pass upwardly throughthe annular space 92 between the inner seal surface 19 and the threadedportion 30 of the hanger body and through the wide open space 93 betweenthe upper end of the hanger body 23 and the lower end of the packerassembly 34, then passing upwardly through an annular passage 94 betweenthe mandrel 46 and the packer assembly, actuator sleeve 32 and seatprotector 35, the by-pass path then continuing through a plurality ofcircumferentially spaced longitudinal openings 95 in the torque sleeveand into the annulus 96 between the tubular running string Y and thesurrounding apparatus to the drilling rig.

The packing assembly 34 includes an upper abutment ring 100 secured tothe lower portion of the threaded packing actuator sleeve 32 by means ofa swivel. Such swivel includes a split snap retainer ring 101 mounted inan external groove 102 in the nut or sleeve 32 and an internal groove103 in the upper abutment ring 100. A thrust bearing 104 is providedbetween the actuator sleeve 32 and the upper abutment ring 100, so thatthe sleeve can be rotated without rotating the ring. As shown, thethrust bearing includes an upper race 105 in the threaded sleeve and alower race 106 in the upper end of the upper abutment ring 100, ballbearings 107 being disposed in these races to allow the sleeve 32 torotate without rotating the upper abutment ring 100.

The lower end of the upper abutment ring 1% engages an initiallyretracted packing element ring 108 made of an elastomer material, suchas rubber or a rubber-like material, the lower end of this packing ringbeing engaged by a lower abutment 109 adapted to engage an upwardlyfacing shoulder 110 on the hanger body 23 below its external surface 28.The packing ring 108 and the lower abutment ring 109 are assembled tothe upper abutment ring 100 by a plurality of cap screws 111 extendingthrough the lower ring and packing ring and threaded into the upperabutment ring, the screws having heads 112 received within counterbores113 in the lower abutment ring 109 and adapted to engage the upper ends114 of the counterbores.

Prior to lowering the casing hanger apparatus and the casing U suspendedtherefrom into the well bore, the casing hanger apparatus has its partsin their relative positions illustrated in FIGS. 2a and 2b, in which thepacking element or ring 108 is retracted and with the actuator sleeve 32and packing assembly 34 occupying their upper positions spaced above thehanger body 23, the actuator sleeve 32 being connected to the seatprotector 35 by the pin and T-slot connections 37, 38 and the seatprotector being connected to the torque sleeve 40 through the pin andJ-slot connections 41, 42. The lower portion of the mandrel 46 issecured to the hanger body by means of the hydraulically actuatableconnection 50.

The casing U is lowered from the drilling rig through the equipmentdisposed above the ocean floor and into the well bore A, the uppermostportion of the casing string being secured to the hanger apparatus Wwhich has its parts in the relative relationship illustrated in FIGS. 2aand 2b. The tapered shoulder 25 of the hanger body 23 will move past theupper lock ring 21 and shift it outwardly out of its way and will thenmove downwardly into engagement with the lower lock ring 17, expandingit more fully into its groove 16 out of its way until the hanger bodyengages its companion seat 15 in the surrounding hanger body K,whereupon the split lock ring 17 will contract inherently across thebody shoulder 27 and lock the hanger body and the casing suspendedtherebelow in place. At this time, the packing abutment 100, or the seatprotector 35 or actuator sleeve 32, is disposed across the upper lockring 21 and the seal ring 39 on the seat protector may be out of sealingrelation to its cornpanion cylindrical seal surface 19 at the upperportion of the outer hanger body K. An upward pull can now be taken onthe running string Y to insure that the hanger body 23 is locked inplace.

Circulating fluid can now be pumped down through the tubular runningstring Y and through the mandrel 46, continuing on down through thecasing U and then passing around its lower end or suitable casing ports(not shown) into the annulus 90 between the suspended casing string andthe well bore, and also between the casing string U and whatever casingstring J is surrounding it. The circulating fluid flows upwardly throughthe body passages 91 and through the annular passage 29 between theinternal and external seal surfaces 19, 28, flowing upwardly between thepacking assembly 34 and the hanger body 23 and also upwardly through theannulus 94, continuing through the by-pass openings in the torque sleeve41) into the annulus 96 around the running string Y to the drilling rig.

The circulating fluid can be followed by the pumping of a suitablecharge of cement down through the running string Y, the apparatus andthe suspended casing string U. This charge of cement passes from thecasing string and moves upwardly through the annulus 90 around thecasing string to the desired height, in a known manner, the fluid inadvance of the charge of cement slurry passing upwardly through theby-pass path through and around the casing hanger apparatus W.

After the cement has been displaced around the suspended casing U, therunning string Y and the mandrel 46 are disconnected from the hangerbody 23, such disconnection being effected hydraulically. As disclosedin FIG. 6b, a dart or plug 134 is lowered down through the runningstring and into the mandrel passage 74, this plug including a body 131having an upper head 132 which will come to rest upon an upwardly facingseat 133 in the mandrel. When the head engages the seat, an upper sideseal ring 134 on the body sealingly engages the wall of the mandrelpassage above the upper ports 73, an intermediate seal ring 135 on thebody engages the wall of the mandrel passage between the upper and lowerports 73, 76, and a lower seal ring 136 on the body engages thewall ofthe mandrel passage below the lower ports 76. A stem 137 is disposedwithin the central passage 138 through the mandrel body, this stemincluding an upper portion 139 having an upper fishing head 140 which isthreadedly secured to a main stem portion disposed within the body. Anupper seal ring 141 on the stem engages the wall of the body bore 138above a plurality of upper ports 142 extending from the central passageof the body to its exterior, communicating with the upper mandrel ports73. An intermediate seal ring 143 is disposed on the stem and sealinglyengages the wall of the body bore 138 above a set of lower ports 144 inthe stem, extending from a central passage 145 running upwardly throughthe stem and communicating with a central passage in the upper stemportion 146 open at its upper end, the stern ports 144 communicatingwith side ports 147 extending through the body 131 in communication withthe mandrel ports 76. A lower seal ring 148 is mounted on the lowerportion of the stem and sealingly engages the wall of the body passagebelow the stem ports 144. A helical spring 149 surrounds a reduceddiameter portion of the stem 137, its upper end bearing against a bodyshoulder 150 and its lower end against a stem shoulder 151, urging thestem in the downward position illustrated in FIG. 6b, limited byengagement of a stem flange 152 with the upper end of the body 131.

When the dart 130 is disposed in the position shown in FIG. 6b, fluidpumped down the running string Y and into the mandrel 46 can flowthrough the stern passages 146, 145 and out through the ports 144, 147of the dart and through the mandrel ports 76 into the lower annularspace 77 between the lower piston 54 and the mandrel, the fluid underpressure acting in an upward direction on the cylinder head 70 andshifting the annular cylinder 61 upwardly along the mandrel to aposition in which the locking dogs or latches 57 are free to shiftinwardly from the hanger body grooves 59. The fluid or liquid in thecylinder space 75 above the head 70 can pass outwardly through the uppermandrel ports 73 and the body ports 142 into the annular spring space153, then continuing downwardly through a discharge passage 154extending through the lower stem, the exhausting fluid then flowing outof the lower end of the lower stem and into the mandrel below the dart.

Following the hydraulic disconnection of the mandrel 46 from the hangerbody 23, the dart 130 can be removed, as by lowering a fishing tool (notshown) on a wire line (not shown) through the drill pipe into couplingengagement with the stem head 140, the wire line and dart then beingpulled through the drill pipe Y to the drilling rig. The running stringY and running tool V are now lowered to lower the packing assembly 34over the hanger body 23 and to bring the actuator sleeve 32 against theupper portion of the hanger body. The drill pipe and mandrel are thenrotated to thread the actuator sleeve 32 downwardly along the threadedbody portion 30, shifting of the packing assembly downwardly until thelower abutment 109 engages the body shoulder 110, at which time theretracted packing sleeve 108 is disposed between the internal andexternal seal surfaces 19, 28. A continuation of the rotation of therunning string and mandrel will effect a continued downward threading ofthe actuator sleeve 32 along the body, moving the upper abutment 100toward the lower abutment 109 and shortening the packing sleeve or ring108 and expanding it outwardly and inwardly into firm sealing engagementwith the internal and external sealing surfaces 19, 28 on the outer andinner hanger bodies K, 23. A suflicient torque is imposed on theapparatus to insure the firm sealing of the packing sleeve 108 againstits companion surfaces. However, it is to be noted that during theentire rotation of the actuator sleeve on the hanger body, torque is nottransmitted to the packing structure, because of the swivel 100107, sothat no twist is imparted to the packing, but only an axial compressiveforce inveifecting its pack-off against the inner seal surface and theexternal seal surface.

The effectiveness of the packed-off seal 108 can now be tested with allof the apparatus remaining in place. A suitable pressure is imposed onthe fluid in the annulus 96 surrounding the tubular running string, as,for example, by closing a blowout preventer N thereagainst and thensubjecting the fluid in the annulus below the blowout preventer toadequate pressure. If no pressure loss occurs, assurance is had that theseal is effective. If a leak is detected, which is determined to be dueto the packing 108, an additional compression of the packing sleeve canbe undertaken by turning the running string Y and the mandrel 46, whichwill effect an additional downward threading of the actuator sleeve 32along the anchor body 23.

Assuming the seal does not leak, the running tool V can now bedisconnected from the seat protector 35 merely by partially turning therunning string Y to the right to be assured that the torque sleevepins41 are disposed against the ends of the J-slots 42 and in alignmentwith its vertical legs 43, whereupon the tubular running string is movedupwardly to move the pins 41 out of the J+slots 42, which permits therunning tool V to be removed from the casing hanger apparatus W andelevated through the equipment thereabove to the .drilling rig, theparts of the casing hanger apparatus then being in the positionillustrated in FIG. 7, with the seat protector 35 in place and with aneffective pack-off existing between the hanger body 23 and the hangerbody K, or other device there around. At this time, it is to be notedthat the downward movement ofthe seat protector will have shifted itsseal ring 39 into sealing engagement with the cylindrical surface 19 ofthe surrounding hanger body K.

When the seat protector 35 is no longer required, it is easily removedby lowering a suitable retrieving tool on a running string. Thisretrieving apparatus may be of the type disclosed in my application forWell Bore Running- In and Retrieving Tool, Ser. No. 503,563, filed Oct.23, 1965, now Patent No. 3,350,130. This tool becomes coupled to theseat protector, as by latching under a downwardly facing shoulder 170 ofan internal groove 171 in the upper portion of the seat protector, withsuitable pins entering the J-slots 42 so as to be coupled to andtransmit torque to the seat protector. The retrieving tool (not shown)can then be appropriately turned, by turning the running string Y, toturn the seat protector 35 relative to the packing actuator sleeve 32and align the torque pins 37 with the vertical legs of the invertedT-slots 38, which will then allow an upward pull to be taken on theapparatus to shift the pins 37 from the T-slots and thereby effect afull disconnection of the seat protector from the actuator sleeve 32,the seat protector being withdrawn with the running string andretrieving tool to the drilling rig above the body of water.

In the event that a leakproof seal is not effected between the packingring 108 and the inner and outer hanger bodies 23, K, the packerassembly 34 can be removed. The retrieving tool shown in the aboveapplication, Ser. No. 503,563, is connected to a tubular string andlowered from the drilling rig into a position in which pins of theretrieving tool, corresponding to the torque pins 37 of the seatprotector 35, move into the T-slots 38, whereupon the running string andretrieving tool are rotated to the left, to unthread the entire packerassembly 34 upwardly of the body and completely disconnect the actuatorsleeve 32 from the body, whereupon the packer assembly can be elevatedto the drilling rig and a new pack-off assembly substituted in itsplace, which is then run, with a seat protector 35 connected thereto,through the equipment above the floor of the ocean and threadedlyconnected to the packer body 23, continued right-hand rotation of therunning string Y, running tool and the packer actuating sleeve 32 againshifting the latter downwardly and effecting a pack-off of the packingring 108 against the internal and external sealing surfaces 19, 28, thepacker assembly then being in the condition illustrated in FIGS. 6b and9. The running tool preferably seals against the internal cylindricalsurface of the casing U in essentially the same manner as disclosed inFIG. 6b, allowing the liquid in the annulus 96 around the running stringto be subjected to pressure to test the effectiveness of the seal.

In the event of removal of the seat protector 35, the upper lock ring 21is in position to lock another hanger body (not shown) from whichanother casing string is suspended, the hanger body resting upon theupper end of the hanger body 23 previously installed, and having ashoulder that will be disposed below the lock ring 21 that will contractpartially out of its internal groove 20 to overlie the shoulder of theadded hanger body in essentially the same manner as the lower lock ring17 overlies the shoulder 27 of the previously installed hanger body. Apack-off can be effected between a packing ring against the seal surface19 above the upper lock ring 21 in essentially the same manner as withthe packing assembly 34 described above, there being a by-pass areaaround and through the apparatus for circulating fluid that passesupwardly through the annulus between the subsequently run casing string(not shown) and the casing string U described above.

It is, accordingly, apparent that well bore casing hanger apparatus hasbeen provided which requires only a single trip into the well bore torun, land, lock the hanger in place, test the lock, circulate fluid,pump cement for sealing and supporting the suspended casing in thedrilled hole, actuate the area of the seal, test the seal, and installthe seat protector. All necessary apparatus is appropriate- 1y assembledat the drilling rig and is run simultaneously into the well bore. Alarge circulation area is present in and around the apparatus. Thepacking element 108 is packed off by being subject to longitudinalcompression only, there being no torque or twisting action imposed uponit. The hanger 23 is locked in place before the cementing operationbegins so that it cannot be pumped off its supporting seat 15. Theeffectiveness of the pack-off of the packing 108 can be tested beforethe running string Y is removed from the hole, and, if necessary, adefective pack-off can be remedied by retrieving the packing structure34, in view of the ability to couple into the packing actuator sleeve 32and reversely rotate and unthread it completely from the hanger body 23.The running string Y is released from the hanger body 23 before thepack-off operation commences, which eliminates the necessity forsubstantial turning of the running string in order to retrieve therunning tool- V from the apparatus that is left connected to the casinghanger body, including the seat protector 35 for a hanger apparatus tobe installed subsequently.

I claim:

1. In well bore casing apparatus: an outer body connectible to an outercasing; an inner body supportable by said outer body for suspending aninner casing within the outer casing; said inner and outer bodiesproviding a fluid passage therebetween communicating with the annularspace between the inner and outer casings; a packing structure forclosing said passage; a mandrel adapted for connection to a runningstring; means releasably connecting said mandrel to said inner body;means releasably connecting said packing structure to said mandrel forsupport solely by said mandred and positioning said packing structureabove and spaced from said inner body; said inner body with the innercasing suspended therefrom and said packing structure being movable as aunit with said mandrel and running string to a position of support ofsaid inner body on said outer body and with said packing structure inopen relation to said passage; and means for shifting said packingstructure from said position above and spaced from said inner body to aposition closing said passage after support of said inner casing on saidouter body.

2. In well bore casing apparatus as defined in claim 1; said meansreleasably connecting said mandrel to said body being constructed andarranged for release prior to shifting of said packing structure to saidposition closing said first-mentioned passage to allow said mandrel tomove downwardly and move said packing structure downwardly therewitharound said inner body and toward said position closing saidfirst-mentioned passage.

3. In well bore casing apparatus as defined in claim 1; and means forreleasing said means releasably connecting said mandrel to said innerbody prior to shifting of said packing structure from said positionabove and spaced from said inner body.

4. In well bore casing apparatus as defined in claim 1; andhydraulically operable means for eifecting release of said mandrel fromsaid inner body.

5. In well bore casing apparatus as defined in claim 1; wherein saidmeans for shifting said packing structure to a position closing saidfirst-mentioned passage is operative in response to rotation of saidmandrel by the running string.

6. In well bore casing apparatus as defined in claim 1; wherein saidmeans for shifting said packing structure includes a threaded portion onsaid inner body and a threaded actuator sleeve disposed initially abovesaid inner body and shiftable downwardly into engagement with said innerbody, and means responsive to rotation of said mandrel by the runningstring for threading said sleeve downwardly of said inner body to shiftsaid packing structure downwardly to said position closing saidfirst-mentioned passage.

7. In well bore casing apparatus: an outer body connectible to an outercasing; an inner body supportable by said outer body for suspending aninner casing within the outer casing; said inner and outer bodiesproviding a fluid passage therebetween communicating with the annularspace between the inner and outer casings; said inner and outer bodieshaving opposed sealing surfaces spaced from each other to provide anannular passage therebetween constituting a portion of said flowpassage; one of said bodies having an upwardly facing shoulder; apacking structure adapted to be moved into said annular passage; amandrel adapted for connection to a running string; means releasablyconnecting said mandrel to said inner body; means releasably connectingsaid packing structure to said mandrel for support solely by saidmandrel and positioning said packing structure above and spaced fromsaid inner body and annular passage; said inner body with the innercasing suspended therefrom and said packing structure being movabledownwardly as a unit with said mandrel and running string to a positionof support of said inner body on said outer body and with said packingstructure in open relation to said annular passage; and means for movingsaid packing structure from said position above and spaced from saidinner body downwardly into said annular passage and against saidshoulder to compress said packing structure against said sealingsurfaces to close said annular passage.

8. In well bore casing apparatu as defined in claim 7; said meansreleasably connecting said mandrel to said body being constructed andarranged for release prior to shifting of said packing structure to saidposition closing said annular passage to allow said mandrel to movedownwardly and move said packing structure downwardly therewith aroundsaid inner body and toward said position closing said annular passage.

9. In well bore casing apparatus as defined in claim 7; and means forreleasing said means releasably connecting said mandrel to said innerbody prior to shifting of said packing structure from said positionabove and spaced from said inner body. I

10. In well bore casing apparatus as defined in claim 7; andhydraulically operable means for effecting release of said mandrel fromaid inner body.

11. In well bore casing apparatus as defined in claim 7; wherein saidmeans for shifting said packing structure to a position closing saidannular passage is operative in response to rotation of said mandrel bythe running string.

12. In well bore casing apparatus as defined in claim 1; wherein saidmeans for shifting said packing structure includes a threaded portion onsaid inner body and a threaded actuator sleeve disposed initially abovesaid inner body and shiftable downwardly into engagement with said innerbody, and means responsive to rotation of said mandrel by the runningstring for threading said sleeve downwardly of said inner body to shiftsaid packing structure downwardly to said position against said sealingsurfaces closing said annular passage.

13. In well bore casing apparatus: an outer body connectible to an outercasing; an inner body supportable by said outer body for suspending aninner casing within the outer casing; said inner and outer bodiesproviding a fluid passage therebetween communicating with the annularspace between the inner and outer casings; a packing structure forclosing said passage; a mandrel adapted for connection to a runningstring; means releasably connecting said mandrel to said inner body;means releasably connecting said packing tructure to said mandrel forsupport solely by said mandrel and positioning said packing structureabove and spaced from said inner body; said packing structure beingspaced laterally from said mandrel to provide a fluid passagetherebetween communicating with said other fluid passage; said innerbody with the inner casing suspended therefrom and said packingstructure being movable as a unit with said mandrel and running stringto a position of support of said inner body on said outer body and withsaid packing structure in open relation to said first-mentioned passage;means for shifting said packing strutcure from said position above andspaced from said inner body to a position closing said first-mentionedfluid passage after support of said inner body on said outer body; andmeans retaining said packing structure in said closed positions.

14. In well bore casing apparatus: an outer body connectible to an outercasing; an inner body supportable by said outer body for suspending aninner casing within the outer casing; said inner and outer bodiesproviding a fluid passage therebetween communicating with the annularspace beeen the inner and outer casings; said inner and outer bodieshaving opposed sealing surfaces spaced from each other to provide anannular passage therebetween constituting a portion of said flowpassage; one of said bodies having an upwardly facing shoulder; apacking structure adapted to be moved into said annular passage; amandrel adapted for connection to a running string; means releasablyconnecting said mandrel to said inner body; means releasably connectingsaid packing structure to said mandrel for support solely by saidmandrel and positioning said packing structure above and spaced fromsaid inner body and annular passage; said packing structure being spacedlaterally flom said mandrel to provide a fluid passage therebetweencommunicating with said other fluid passage; said inner body with theinner casing suspended therefrom and said packing structure beingmovable downwardly as a unit with said mandrel and running string to aposition of support of said inner body on said outer body and with saidpacking structure in open relation to said annular passage; means formoving said packing structure from said position above and spaced fromsaid inner body downwardly into said annular passage and against saidshoulder to compress said packing structure against said sealingsurfaces to close said annular passage; and means retaining said packingstructure in said closed position.

References Cited UNITED STATES PATENTS 10 CARL W. TOMLIN, PrimaryExaminer DAVE W. AROLA, Assistant Examiner US. Cl. X.R.

